Perhaps I am overlooking something simple. I have no experience with (digital) Tek scopes. No of them seems to be doing something.įrom the video, and monitoring addresslines, it seems the processor is running, but maybe it encounters some sort of error. The digital push buttons are electrically OK, also the cursor pot (checked with ather scope). The controller heatsink itself is touchable, so no overheating. Tested real-time, and in testmode.Ĭhanged the processor (recovered from a very old Epson XT PC), no change.Ĭhecked the display controller socket, but nothing unusual. shorts between addressline or outputs behaving strange. There are no leaking or thick capacitors in the PSU (Why do they make is so difficult to remove te cover?)ĭata- and addresslines do not show unlogical signals, ie.
#Hameg hm205 3 service manual plus
Voltages are OK, also the plus and minus 15V on the vector board. I have tested and measured all sort of things, but there is nothing that looks not normal at first sight.
#Hameg hm205 3 service manual manual
I have a nice service manual (Artek Media). Pushing the select on the cursor pot or turning it has no effect. So, the fuzzy readout the previuos owner saw was this behaviour. While pushing beamfind, it looks like some diagnostic things are displayed, but you cannot recognize any text. When you push beamfind, there is some small rectangular image somewhere, this can be top or bottom, an left or right.Īfter some time, after 1:20" in the video, things start to change. (Except for an issue with the attenuator which looks to be open in some positions, bad contact?).Īfter some time, after 40" in the video, the analog screen disappears completely. On startup, the analog function looks OK, all the controls are functional. The GPIB option board is present, as well as the memory option. Inside there is no dust, and no repairs have been done previously. Or if it has even worked as it should be. The scope is very clean and probably not used very much, if it ever has been used. I always find it a challenge to repair electronic equipment, but this time I am stuck. The previuos owner could remember het go it from somebody else, and there was something about a fuzzy readout. After pressing/releasing it a couple of times, it's almost back to normal.I have been given a Tektronix 2230 scope. I think there was a faulty contact at the X-Y-switch. EDIT: While writing this, both of the scopes just magically recovered from half-broken to fully alive. Where could I look next? Is that a common fault? After all, this affects two of two devices which I have here. With this background, I suspect that the error is located somewhere around the generation or, more probably, in the amplification of the analog time base. Also, the 5 Volts for supplying the time base are present. They all seem ok, except 4,89 V instead of 5 Volt but that might be ok anyway. (Image A and B.) With the schematics at hand ( ), what i did so far was checking power supply voltages, +12V, -12, +5 V, +150 V, +130 V, on the "XY-04". (Image C.) 4) In digital storage mode, everything works as expected, also I can shift towards + or - x. (Similar to image E.) 3) component tester is able to produce a trace that can be shiftet in horizontal direction by rotating x-pos knob. However it doesn't seem to be affected by x position control. Also here, the diffuse light moves accordingly when I rotate the y-position control. (Image D and E.) 2) XY-Mode does not work either in the sense that there is no focused dot on the screen, just a dim diffuse light towards the right of the screen. Cannot judge if x-control has any affect on the flickering. y position control seems to work, as it affects the flickering towards up / down the screen. But there is a flickering in sync with the time base (repeatedly from bright to dark), so I can adjust the flickering from slow to fast.
1) In analog mode (storage button not pressed) I don't see any trace. In both cases the classical analog time base does not work. Interestingly enough both have the same error.
Hi, I have two of these HM 205-3 storage scopes.
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